code: def test_forward_test(self):
      feat = torch.randn(2, 512, 8, 8)
      encoder_out = torch.randn(2, 128, 8, 8)
      self.decoder.eval()
      output = self.decoder(
          feat=feat, out_enc=encoder_out, data_samples=self.data_info
      )
      self.assertTupleEqual(tuple(output.shape), (2, 40, 39))
  
file_path: mmocr/tests/test_models/test_textrecog/test_decoders/test_robust_scanner_fuser.py
imports: from unittest import TestCase
  import torch
  from mmengine.structures import LabelData
  from mmocr.models.textrecog.decoders import PositionAttentionDecoder, RobustScannerFuser, SequenceAttentionDecoder
  from mmocr.structures import TextRecogDataSample
label_desc: Use image node_id 4 for calling the TestRobustScannerFuser obj's underlying member method code with example usage: obj.test_forward_test() without return types